TM 5-3895-346-14
ENGINE OVERHAUL
FUEL INJECTOR
Wash the spray tip in clean fuel oil and dry it with compressed air.
Clean and brush all of the passages in the injector body using fuel hole cleaning brush J 8152 and rack hole
cleaning brush J 8150. Blow out the passages and dry them with compressed air.
Carefully insert reamer J 21089 in the injector body (Fig. 29). Turn it in a clockwise direction a few turns, then
remove the reamer and check the face of the ring for reamer contact over the entire face of the ring. If
necessary, repeat the reaming procedure until the reamer does make contact with the entire face of the ring.
Clean up the opposite side of the ring in the same manner.
Carefully insert a 0.375-inch-diameter straight-fluted reamer inside the ring bore in the injector body. Turn the
reamer in a clockwise direction and remove any burrs inside the ring bore. Then wash the injector body in
clean fuel oil and dry it with compressed air.
Remove the carbon deposits from the lower inside diameter taper of the in- jector nut with carbon remover J
9418-5 (Fig. 30). Use care to minimize removing metal or setting up burrs on the spray tip seat. Remove only
enough metal to produce a clean uniform seat to prevent leakage between the tip and the nut. Carefully insert
carbon re- mover J 9418-1 in the injector nut. Turn it clockwise to remove the carbon deposits on the flat spray
tip seat.
Wash the injector nut in clean fuel oil and dry it with compressed air. Carbon deposits on the spray tip seating
surface of the injector nut will result in poor sealing and consequent fuel leakage around the spray tip.
When handling the injector plunger, do not touch the finished plunger surfaces with your fingers. Wash the
plunger and bushing with clean fuel oil and dry them with compressed air. Be sure the high-pressure bleed hole
in the side of the bushing is not plugged. If this hole is plugged, fuel leakage will occur at the upper end of the
bushing where it will drain out of the injector body vent and rack holes during engine operation, causing a
serious oil dilution problem.
NOTE
Keep the plunger and bushing together, as they are mated parts.
After washing, submerge the parts in a clean receptacle containing clean fuel oil.
Figure 29. Cleaning Injector Body Ring with Tool
Figure 30. Cleaning Injector Nut Spray Tip with
J 21089
Tool J 9418-5
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